The present invention relates to an inflator for inflating an inflatable device, such as an air bag of a vehicle occupant restraint system. More specifically, the present invention relates to an inflator including a container defining a chamber in which gas under pressure is stored and having a rupturable wall that ruptures to provide a gas exit.
U.S. Pat. No. 3,723,205 discloses an inflator for inflating an air bag including a container which contains gas under pressure and a gas generating solid material. When the air bag is to be inflated, a squib is actuated to ignite the gas generating solid material in the container. As the gas generating solid material is burned, the pressure in the container is increased by the heat resulting from combustion of the gas generating solid material. When a predetermined pressure is reached, a rupture disk is ruptured to enable gas to flow from the container to the air bag.
Another inflator for inflating an air bag is disclosed in U.S. Pat. No. 5,273,312. The inflator disclosed in U.S. Pat. No. 5,273,312 includes a container which contains a gas under pressure and a gas generating solid material. The container is closed by a rupture disk. A pyrotechnic charge, when ignited, generates pressure against a head of a piston to move the piston. The moving piston ruptures the rupture disk to release a flow of gas from the container. The ignited pyrotechnic charge also generates combustion products which are conducted to the gas generating solid material through a passage that extends through the piston. The combustion products ignite the gas generating solid material which then produces gas and heat that increase the pressure in the container. The pressurized gas flows from the container to the air bag to inflate the air bag.
An inflator disclosed in U.S. Pat. No. 5,263,740 includes a container which contains a gas under pressure. The container is closed by a rupture disk. An igniter is located outside the container directly adjacent the rupture disk, and when ignited produces a pressure wave that ruptures the disk.